Zimmer Ends Relationship with Doctor Following Criticism of Knee Device

A prominent surgeon who was once a consultant for Zimmer Holdings, a maker of surgical tools and joint replacements, thinks the company may have terminated its relationship with him because he questioned the performance of one of its artificial knee componentss. According to The New York Times, Dr. Richard A. Berger has alleged that a version of Zimmer’s NexGen CR-Flex Porous Femoral Component is prone to premature failure.

According to The New York Times, when his relationship with Zimmer commenced, Dr. Berger was finishing his fellowship at the Rush University Medical Center in Chicago at the time, one of the countryâ€™s top centers for joint replacement. He was pioneering a type of small-incision surgery that allowed patients to leave the hospital on the day of surgery.

Zimmer, for its part, had started promoting minimally invasive surgery to distinguish itself from its competitors. To that end, it had trained doctors in the procedure, using its device, the Times said.

In 2002, Dr. Berger was prominently featured in a press release about Zimmerâ€™s plans to build a training facility for minimally invasive surgery. Dr. Berger told the Times he helped train hundreds of surgeons on Zimmerâ€™s behalf, and was soon performing about 1,000 hip and knee replacements annually, nearly all with Zimmer devices. He and his technique received big play in the media. According to the Times, Zimmer portrayed Dr. Berger as a master surgeon and paid him more than $8 million over a decade.

The trouble started when Dr. Berger implanted the NexGen CR-Flex Porous Femoral Component in about 125 patients in 2005. That component relies on the bone naturally fusing with the implant, rather than a cement-like adhesive to bond the thigh bone to the portion of the device that bends. As the Times explained, Dr. Berger and some other specialists prefer this type of device because an adhesive can break down and cause the joint to fail.

According to the Times, by 2006 X-rays of some of Dr. Berger’s patients indicated that the device was loose and had not fused completely. Patients were reporting pain, apparently a result of the loose joint. At that point, he reported the problems to Zimmer, but the company pointed to the success of the NexGen CR-Flex Porous Femoral Component. However, according to The New York Times, Zimmer did not have separate test data on the un-cemented model because the U.S. Food & Drug Administration (FDA) had not required the company to study it in patients before selling it.

Later, when Dr. Berger reported to Zimmer that he had to replace the device in some patients, company officials suggested his technique was to blame for the problems. Zimmer claimed that no other surgeons had made similar complaints.

By 2007, Dr. Berger had stopped using the NexGen CR-Flex Porous Femoral Component . According to him, several other surgeons had reported similar problems. He and one of those surgeons, Dr. Craig J. Della Valle, decided to conduct a study, and according to the Times, found that the NexGen CR-Flex Porous Femoral Component failed early in about 9 percent of some 100 patients they looked at. Signs of looseness were seen in about half of the patients, Dr. Berger told the Times.

Dr. Berger and Dr. Della Valle presented their study at a national meeting of the American Association of Orthopedic Surgeons last year. But according to the Times, Zimmer wasn’t convinced by their findings, citing positive results in a large database of orthopedic patients in Australia.

Last year, Zimmer chose not give Dr. Berger a new contract.

For his part, Dr. Berger told the Times that he has lost confidence in the company. He is trying out other products, and is considering a consulting relationship with another firm.